Production of motor fuel



y 1945. a. a OBERFELL ETAL 2,376,077

PRODUCTION. OF MOTOR FUEL Filed March 14, 1941 2 Sheets-Sheet lDEHYDROGENATION Y ETHANE PROPANE 128 DEHYDROGENA I 46 AROMAT ZAT IONDEHYDROGENAT ION INVENTOR GEORGE G. OBERFELL NES BY JEAN P. O

- A ORNEY y 1945. a. G. OIBVERFELL ET AL 2,376,077

PRODUCTION MOTOR FUEL Filed March 14, 1941 v .2 Sheets-Sheet 2 CATALYTICALKYLATION IZATION RE FORM N6 252 2s| Y SEPARAT INVENTOR GEORGE e.OBERFELL BY JEAN P. JONES Patented May 15, 1945 UNITED STATES PATENTOFFICE PRODUCTION OF MOTOR FUEL George G. Oberfell and Jean P. Jones,Battlesville, Okla., assignors to Phillips Petroleum Company,acorporation of Delaware Application March 14, 1941, Serial No. 383,430

9 Claims.

tor fuels having gasoline characteristics and premium qualitiesespecially as to antidetonating values from hydrocarbons available inso-called wet natural gases. It relates still more particularly to theproduction of such motor fuels in high yields by the utilization of themajor part of the 10 C2 and heavier hydrocarbons'available in naturalgas.

By far the outstanding trend in motor fuels in recent years has been thetendency toward increase in antidetonating characteristics as measuredby increase in octane numbers. Automobile manufacturers havecontinuously designed their cars to make use of the increased efflcienoyand performance afi'orded by high octane gasolines,-

and refiners have attempted above all to produce go rally occurringnormally gaseous mixtures, was in a great demand among refiners becausethe vapor pressure and volatility afforded by blending natural gasolinewith their products allowed them to acteristics of volatile fuels,volatility became the most desired quality, and gasoline and naturalgasoline as a blending stock appeared to be the only means to obtainthis volatility.

The use of cracking processes for manufacturing gasoline was originallymotivated by the desire for higher yields of gasoline and has more recently been stimulated by the demand for higheroctane numbers. Likewisethe more recent use of gas conversion processes has resulted inincreased yields of motor fuel stocks with high octane numbers and hasalso resulted in'the use of lighter hydrocarbon fractions available fromnatural sources which formerly were wasted. However, from the view pointof the natural gasoline industries perhaps the most important effect ofcracking and gas conversion processes was the production of morevolatile motor fuel stocks in the refineries. As an example of thesetrends, in Mid-Continent gasolines, during thepast 15 years Table I ispresented, which shows clearly that while the volatility of motor fuelshas been increasing for many years, this increase has been more thanmade up by volatile fractions produced at refineries, and there hasresulted a decrease rather than an increase in the amount of naturalgasoline used per gallon of finished gasoline product.

TABLE I Estimated composition of motor fuel (per cent by volume)Constituent Years l Refinery base (50% evaporated at 284 F.) (includesstraight run and heavier cracked frac- 2 Volatile refinery products(volatility characteristics based on 12 lb. natural) (includes vaporrecovery and light cracked fractions) 3 Natural gasoline (12 lb. vaporpressure) Ne Ii- 2. 8 9. 4 20. 1 20. 2 20. 5

.gi le 6.2 7.1 7.4 7.0 7.1 6.9

4 Butane.(natural and refinery) out deeper into the kerosine fractionsof crude oil and thus produce higher yields of gasoline. Minimumvolatility speciflcations'were some of the most important specificationsatthat time, and the most dimcult ones to meet. Moreover, with Inaddition to this, natural gasoline constitutes only a small proportionof the hydrocarbon material available in natural occurring normallygaseous hydrocarbon stocks such as natural gas. In Table II is shown incolumn 1 the composition of the recognition of the superior performancechara natural gas which may be assumed to be typical.

Tan: 11

Raw natural gasoline, 125' A. P. I.

l 2 I 3 4 5 t N tural I'lmlfld M l li r i l i Com hen a v 0 gm 0 qpogas, mol per per uid, vol; per g? per cent cent cent cent Methane 87.02.2 3.1 Ethane 6. 0 l0. 0 l2. 0 Propane 4.0 37.0 40.3 Isobutane. 1 7 7.97.2 N-butane- 24.0 22.8 Isopenhne.-. 5. 6 4. 6 N- tane. 4.9 4.2 Iso l. 33. 3 2. N-henne 2.2 1.6 Heptanes and 3. 0 l. 7

heavier A very large proportion of this natural gas is methane which asyet is still practically unavailable for conversion in the motor fuelstocks. Only about 3 mol per cent of this natural gas comprises 04 andheavier hydrocarbons, which are normally included in natural gasolines,and although there is a large proportion of natural gas which ismethane, there is roughly three times as much ethane and propane asmaterial available directly for natural gasoline. Processes are nowavailable which without undue expense can extract substantially all ofthe C: and heavier hydrocarbons from such natural gas. Column 2 and 3respectively of Table II show the composition of the product which canbe extracted from this natural gas in commercial quantities withoutundue expense. It will be noted that although this product contains onlya small portion of the available ethane, nevertheless on a liquid volumebasis not more than about 30% comprises those constituents which make upnatural gasoline, since ordinarily only about one-half or less of thebutanes are included to form a 26-70 natural gasoline. The approximatecomposition of a natural gasoline blending stock known to the trade as26-70 natural gasoline is shown in column 4, together with the octanenumber of the principle fractions which are shown in column 5.

The lightest third of 26-70 natural gasoline is butane hydrocarbonswhose vapor pressure makes it unsuitable for blending directly intomotor fuel in any large proportion. Because of the limitations to itsuse as a blending stock large quantities of butane are now beingprocessed in polymerization operations or are being marketed as such ina variety of fuel applications. Half of the remainder of naturalgasoline consists of pentanes which are hydrocarbons of intermediatevapor pressure but which have a high volatility so that these materialscan not be used in large percentages in blending with many other motorfuel stocks because of their effect in increase in the volatility of thefinal gasoline product as indicated by the percentage evaporated at 212F.

The other half of butane-free natural gasoline is a low vapor pressurehexane and heavier fraction. About ten years ago this fraction had anoctane number which compared favorably with the average octane number ofmotor fuels of that time. However, at present the average octane numberof most of the gasolines on the market is around 75 or even higher andas a result the low octane number of this portion of natural gasolineplaces it in the same class as low end point straight run gasoline.

It is. therefore, readily seen that in order to utilize naturaloccurring low boiling hydrocarbone to the maximum advantage it isnecessary to increase the octane number of fractions of low volatilitywhich are directly available as well as to convert hydrocarbons-of 2-5carbon atom per molecule into hydrocarbon fractions which have highoctane numbers and which are not highly volatile.

We have now invented a process which produces high yields of motor fuelstocks having gasoline characteristics, or suitable for. blending stocksto produce such gasolines, which utilizes to a high degree of emciencysubstantially all of the C2 and heavier hydrocarbons which can beobtained from natural gas, or similar hydrocarbon sources, by acombination'of process steps which not only cooperate to produceproducts which.

may be successfully blended together, but which are also socooperatively combined that byproduct fractions from one proces step areefficiently utilized in other process steps along with hydrocarbonfractions primarily charged to such other process steps. l

It is an object of our invention to produce a motor fuel stock of highvalue from lower boiling hydrocarbons.

Another object of our invention is to utilize the ethane and heavierconstituents of natural gas to maximum advantage in the production ofmotor fuel.

A further object of our invention is to establish a process for treatingnaturally occurring gaseous and liquid hydrocarbons to produce acomposite blended motor fuel with well balanced characteristics.

Another object of our invention is to produce from any mixture ormixtures of normally gaseous hydrocarbons of limited methane content amotor fuel having high antiknock qualities, and to produce such a motorfuel in a particularly high yield with reference to the hydrocarbonstreated and/or available.

Still another object is to separate from a natural gas substantially allof the C2 and heavier 45.hydrocarbon content therein and to producetherefrom a normally liquid motor fuel whose volatility, saturatecontent, and aromaticity may be varied at will.

Still another object of our invention is to establish a process in whichseparate constituents of a hydrocarbon mixture extracted from a wetnatural gas are subjected to various conversion steps to produce motorfuel stocks which can be blended together to produce a composite motorfuel of gasoline characteristics, the said conversion steps cooperatingamong themselves to effect the conversions in an optimum manner withhigh yields.

Other objects and advantages of our invention will become apparent fromthe accompanying description and disclosure.

In the present specification and claims by m0- tor fuel of gasolinecharacteristics is meant a hydrocarbon mixture, which may or may notcontain small amounts of added chemicals such as antidetonants and guminhibitors and the like. which will meet any set of the variousspecifications recognized in the trade for gasoline. As an example ofsuch specifications the following Table III is quoted from the Bureau ofMines Report of Investigations 3492. These, however, are not necessarilyto be considered limiting as to any particular characteristic or groupof characteristics. In addition to the characteristics shown, it isassumed that all the gasolines are sweet and contain inhibitors toprevent excessive gum formation where necessary, and meet any otherqualifications usual to the trade.

Tun: 111

Motor gasoline survey (ranges of 90% of fuels tested) Regular pricePremium price gasoliues gasolines Summer Winter Summer Winter 19361938-33 1036 1038-39 Gravity... API.. 56. 8-62. 59.1-66. 6 56.9-05. 659. 3-669 Sulfur. -.per cent 0. 023-0. 20 0. 026-0. 24 0. 019-0. 087 0.021-0. 087 Reid vapor pr'essure 6. 0-9. 1 8. 4-12. 1 5. 2-8. 8 7. 5-11.7 68. 0-71. 0 69. 4-72. 5 74. 0-81. 0 75. 9-81.13

94-114 83-97 95-118 85-1 135-161 114-141 133-164 118-147 160-192 133-174159-188 138-175 180-218 154-201 176-214 158-199 229-264 209-255 206-257203-246 273-310 264-304 239-306 236-293 335-371 336-371 286-365 280-363End point 383-419 386-415 343-417 360-413 Distillation 1055.. 1. 0-2.5 1. 3-3. 4 0. 8-2. 3 1.0-3. 2

Reference will nowbe made to the drawing which forms a part of thespecification and which diagrammatically illustrates by way of a flowsheet an arrangement of apparatus in which our invention, together withvarious modifications thereof, may be practiced. In the description ofthis drawing the various process steps will be described in connectionwith optimum conditions for their operation, which'will serve asexamples thereof,

Referring now to the drawing;a suitable hydrocarbon mixture, such as thenatural gas whose composition was given in Table II or such as the rawnatural gasoline separated therefrom whose composition is also given inthis table, is charged to a suitable separating apparatus ll throughpipe "I. The separating or fractionating apparatus II isdiagrammatically illustrated as a fractionating column. It will beappreciated, however, that in actual practice if fractional distillationmeans only are used, such a separation as is to be hereinafter describedwill ordinarily require a series of fractionating columns together withnormally occurring attendant auxiliary apparatus, and that in many casesit will be desirable to conduct at least one or more of the separationsby means of absorbents such as are well known to the art. Extremelylight constituents such as methane and inert gases may be removedthrough a pipe 12 controlled by a valve 13. It is not primarily anobject of this invention to A. Ethane B. Propane C. Isobutane D. Normalbutane E. Isopentane 1". Normalpentane Ci. Hexanes and heavier (in thegasoline range) dehydrogenated in the presence of any one ofa largenumber of known dehydrogenation catalysts, it is very satisfactorilydehydrogenated in the absence of catalysts by being heated to a hightemperature at a low pressure.

. for such a thermal dehydrogenation are a temperature between about1200 and 1500 F. and a pressure not substantially in excess of 100pounds per square inch, preferably about 5-30 pounds per square inchgauge, for a period of time such as to efl'ect a content of about 10 or15 to 40 or '45 per cent unsaturates in the efiluenti gases. Thisdehydrogenation is readily accomplished by passing the ethane fractionthrough a suitable tube coil in a furnace. The dehydrogenation eflluentis passed through pipe 20 to separating means 21 wherein a normallygaseous unsaturated hydrocarbon fraction, which will be predominantlyethylene, is separated from other constituents. Light gases comprisingprimarily methane and hydrogen are removed from the process through apipe 22 and controlled by valve 23. Undesirably heavy hydrocarbons areremoved from the process through a pipe 24 controlled by valve 25. The'separatingmeans 21 will generally be so operated that the ethylenefraction will also generally contain unsaturated Ca hydrocarbons and mayalso contain unsaturated C4 hydrocarbons when their presence is notdeleterious in the subsequent reaction steps, as well as correspondingparailfins. Such an ethylene fraction is removed through a pipe 26 forsubsequent reaction with heavier hydrocarbon fractions as will behereinafter discussed. A suitable ethane fraction from an outsidesource, or separated from other process steps of our invention, may beintroduced through pipe 21 and valve 28 to pipe ii.

In many methods of operation it will be found desirable to include asubstantial part of the protreat hydrocarbons which boil substantiallyabove the end point of gasoline, that is above about 400 to 450 F.,' andany such heavy hydrocarbons which may be present in the material chargedthrough the pipe l0 may be removed from the so large that the fractioncan not be satisfactorily identified as shown. In some instances anindividual fraction may comprise the indicated hydrocarbon in a purityof about 95 per cent or more.

pane present in the material charged through pipe I 0 in the ethanefraction for conversion into ethylene and propylene, so that thefraction will be better termed an ethane-propane" fraction. In mostinstances, however, it will be desirable to separate at least asubstantial portion of the propane fraction for separate treatment. Inthese cases a propane fraction is removed from the separating means Hthrough pipe 30 and valve 3| and is passed through valve 32 to a reacton zone illustrated by reaction coil 33, situated in a suitable furnaceor the like 34, wherein the propane is reacted under alkylationconditions with ethylene, produced in the step just descr bed, which ispassed from pipe 28 through a pipe 35 and is introduced to the reactionmixture and reaction zone 33, preferablyat a plurality of points, suchas are represented by pipes 36 and 3'! controlled Such conditions ature,pressure and reaction time should be so controlled that appreciableconversion of propane by itself would ordinarily not take place. The

unsaturates are so introduced that their concentration at any one pointwill not exceed about 10 per cent by weight, and in many instances willnot be in excess of about 1 or 2 per cent by weight. The efliuent ofthis alkylation step is passed through a pipe 40 and a valve 4| to asuitable separation means 42. The products of the reaction will beprimarily C5 to Ca hydrocarbons, isopentane being the predominant singlehydrocarbon. An isopentane fraction is removed from separating means 42through a pipe 41, and may be discharged from the system for any desireduse through a valve 0 or may e passed from pipe I! through pipe III, forfurther use within the process as will be described, and/or through pipe2" for blending with other products. Light hydrocarbons may be removedfrom the process and from separating means 42 through a pipe 03controlled by a valve 4|. This fraction will generally comprise thelarger part of the unreacted propane and lighter hydrocarbons which maybe separated and returned to the system either directly to separatingmeans II as through pipe It, or may be mixed directly with thecorrespondin fraction or fractions removed through pipe It by beingadded thereto through pipe 50 and valve 5| for propane, or through pipe21 for ethane. A normal pentane fraction, which may contain heavierhydrocarbons in the gasoline range, may be removed from separating means42 through a pipe I! and may be discharged from through valve 53, or maybe passed through pipe 54 and valve 55 for subsequent use in the processas will be hereinafter described. Heavier hydrocarbons may be removedfrom separator 42 and from the process through pipe 45 controlled byvalve 4..

In many cases at least a portion of the propane fraction may besubjected to more or less nondestructive dehydrogenation to formpropylene for su nt reaction in a catalytic alkylation step to bedescribed. In such a case a suitable portion of the propane fraction maybe removed from pipe through a pipe 56 and valve 51 to a dehydrogenationunit II. The dehydrogenation in unit 58 may be carried outnoncatalytically. but in most cases it will be preferable to conduct amore or less clean-cut dehydrogenation to propylene with a minimumproduction of ethylene, and this is best accomplished by use of asuitable dehydrogenation catalyst such as chromium oxide, alone or inadmixture with other oxides such as are known to the art. Thedehydrogenation temperatures should generally be between 900 and 13001". preferably about 950 to 1200 F., and pressure should not be inexcess of 100 pounds per square inch, and will preferably be between 5and 30 pounds per square inch gauge. The reaction time should be suchthat about 15 to 30 or 40 per cent of the eiiiuent is unsaturatedhydrocarbon material. The eiliuent or the dehydrogenation the processunit I. is passed through the pipe 59 to the separating means 00. Whendesired light materials, which will be primarily hydrogen together withsome methane, may be removed from separating means ll and from theprocess through pipe 6| controlled by valve 82. A hydrocarbon fractioncontaining the desired unsaturated hydrocarbons are removed through pipe83 and valve 64 for subsequent use as will be hereinafter described.Heavier hydrocarbons present may be removed through a pipe 65 and avalve68.

An isobutane fraction is removed from separator means il through a pipe10 and valve 1i and may be passed through valve 12 to a suitablealkylation unit such as is represented by reaction coil 13 located in afurnace or other suitable heating means ll. Unsaturated C: and/or C3hydrocarbons produced in dehydrogenation unit It may be passed to thealkylation unit I3 from pipe 20, and are preferably introduced to thereaction mixture in the reaction zone 13 at a plurality of points, suchas are represented by pipes 16 and I1 controlled by valves 18 and 19respectively. The reaction in coil 13 is preferably conducted underconditions substantially the same ashas been discussed in connectionwith the alkylation of propane with a similar unsaturated material inreaction coil 33. When the unsaturated hydrocarbon material passedthrough pipe 26 is primarily ethylene, the principal product produced bythe alkylation in coil 13 under these conditions will be hexanes,heptanes and octanes, of which the predominant constituent will beneohexane. The eiliuent of the reaction coil 73 is passed through a pipeand valve 8| to separating means 82. A suitable alkylate fraction, whichmay under suitable conditions be substantially pure neohexane, isremoved from separating means 82 through a pipe 83 and may be dischargedfrom the process through valve 84 or part or all of the fraction may bepassed through pipe 85 and valve 88 to pipe 255 for blending with otherproducts, as will be described. Undesirably light material will beremoved from separatin means 82 through pipe 81 controlled by valve 88and undesirably heavy material may be removed through 89 controlled byvalve 90. An unreacted C4 hydrocarbon fraction is removed fromseparating means 82 through a pipe 9i and may be passed entirely or inpart back to pipe 10 through valve 92. This hydrocarbon fraction willcontain an appreciable although small amount of unsaturatedhydrocarbons, and since it also has a very high proportion of lsobutaneit will serve as an excellent charge stock for catalytic alkylation withother low boiling unsaturated hydrocarbons. To accomplish this a part orall 01' the material passing through pipe 9| may be removed through pipe98 controlled by a valve 94 and passed to a catalytic alkylation unit95. In many instances a substantial portion of the isobutane may bepassed directly from pipe 10 throu h ipe 96 and Y valve 9! to pipe 93and this catalytic alkylation step.

The proylene fraction produced by dehydroenation in unit 58 serves as anexcellent source of unsaturated material for this catalytic alkylationand may be introduced into pipe 93 from pipe 63 for this reaction. Inalkylation unit 95 the hydrocarbons brought thereinto by pi e 93 aretreated in the presence of a suitable alkylation calatlyst to formisoparafllns predominantly of 7 and 8 carbon atoms per molecule, whichhave high octane numbers and low volatility and are therefore desirableingredients for the as'rao'rv I gasoline product of our invention. Thealkylation process preferably uses a catalyst such as an aluminum halidecatalyst, especially aluminum chloride or bromide or any one of numeronemetal halo-aluminates known to the art such as sodium chloro-aluminate,or zinc chloride or bromide, boron fluoride or zirconium tetrachlorideor the like, or concentrated sulfuric acid, or concentrated hydrofluoricacid.

It a catalytic alkylation process involving a liquid or a mobilecatalyst is used, the catalyst may be fed to the system through pipe 00controlled by valve 99. In such a process it is advantageous to usesulfuric acid or hydrofluoric acid as the catalyst, since thesecatalysts appear to be more selective than some of the other alkylationcatalysts for the alkylation of isoparafilns, and cause a minimum ofside reactions. To minimize concurrent polymerization reactions themixtur of hydrocarbons in the catalyst should be intimately contacted,and the concentration of unsaturated hydrocarbons in any one portion ofthe mixture preferably should be kept low relative to the concentrationof isoparaflins, as may be effected by multipoint addition of olefins toa reacting stream, recirculation of a portion of the reactants in aclosed cycle, and the like. In most instances a suitable reactiontemperature will be found between about 0 and 125 F., generally betweenabout and 10 F., although higher or lower temperatures may be used, asmay be found most suitable for the catalyst used. The hydrocarbonefiluent is passed through a pipe I00 to a separator IOI wherein heavy,hydrocarbon-immiscible material is separated from the hydrocarbons andremoved through a pipe I02 controlled by valve I03. When sulfuric acidor hydrofluoric acid is used as the alkylation catalyst, a substantialportion of this material may often be passed directly from pipe I02 topipe 90 for re-use in the process. A hydrocarbon eiiluent of thecatalytic alkylationis passed from separator IOI through a pipe I04controlled by a valve I05 to a separating means I06. An alkylate productis removed from separating means I05 through a pipe I01, and may bedischarged from the process through valve I08 but in most cases thisproduct will be passed from pipe 101 through pipe I09 controlled by avalve IIO to pipe 255 for blending with other hydrocarbon fractionsproduced from other steps of the process to give a. finished gasolineproduct.

Any undesirable low boiling material which is present in the efliuent ofthe catalytic alkylation step may be removed from separator I06 and fromthe process through pipe H9 controlled by valve I29, and intermediatefraction such as propane and/or butane may be removed from separatingmeans I05 through pipe II1 controlled by valve II8, and may be returnedto the process in the most suitable manner. Heavy hydrocarbons may beremoved through pipe I48 controlled by valve I49.

The isopentane fraction separated from separating means 42 through pipe41, having been produced by thermal alkylation, will often contain asmall but appreciable amount of unsaturated hydrocarbons especially ifthis fraction is so separated that it contains a substantial portion ofthe C4 hydrocarbons produced in the process. For instance, such afraction recovered from an alkylation of propane with ethylene hadsubstantially the following composition.

M01 per cent Component At least a part of this material may well make asuitable charge stock for the catalytic alkylation process justdescribed, and its use will tend to produce an alkylate product of highoctane number and still lower volatility. To this end a suitable portionof this isopentane fraction may be removed from pipe 41 through pipe IIIcontrolled by a valve II2, which passes directly to pipe '93. In somecases it may be desirable to submit a. portion of this material toalkylation in the unit 13, and if such is the case a portion thereof maybe passed from pipe III through pipe 3 controlled by a valve II4 passingto pipe 10. Isobutane or isopentane from any desirable outside source,or separated from any of the streams discharged from this process, maybe introduced to pipe 10 through pipe II5 controlled by valve II6.

A normal butane fraction is removed from separating means II throughpipe I20 controlled by a valve I2I. This normal butane fraction 80 maybe treated in any one or more of several manners about to be described,or a portion thereof may be included directly in a final blendedgasoline product. When a portion is to be blended with the gasolinedirectly, it may be passed from pipe I20 through pipe I22 and valves I23and I24 to pipe 255, or if desired the portion thereof may be removedfrom the system through a pipe I25 controlled by a valve I26. Normalbutane may be advantageously dehydrogenated to form normal butenes whichcan then be reacted genation carried out in unit I30 is preferably acatalytic operation, more or less as has been discussed for thecatalytic dehydrogenation of the propane fraction in the dehydrogenationunit 58. The optimum temperature for the dehydrogenation of normalbutane is somewhat lower than that for the dehydrogenation of propaneand will generally be found within the range of 850 to 1150 F.preferably between about 900 and 1050 F. The dehydrogenation pressureshould again not be in excess of about pounds per square inch, andpreferably .is between about 5 and 30 pounds per square inch gauge, witha reaction time such thaththe effluent contains between about 10 and 35or 40 per cent of unsaturates and generally between about 15 and 25 percent of unsaturates. Any suitable dehydrogenation catalyst known to theart may be used although we prefer to utilize a catalyst comprisingchromium oxide. The dehydrogenation efiluent is passed from unit I30through pipe I3I to suitable separating means I32. A 04 fractioncontaining butenes produced by the dehydrogenation, and which may alsocontain other hydrocarbons such as propylene and/or pentenes which havealso been formed in small amounts in the dehydrogenation, is removedfrom separating means I02 through a pip I 33 and valve I and isintroduced to the catalytic alkylation unit 80 by being passed to pipe83. Undesired low boiling material produced by the dehydrogenation isremoved from separating means I02 through a pipe I80 controlled by avalve I80. Any heavier hydrocarbons produced as by-products of theprocess may be removed therefrom through pipe I31 controlled by valveIl0. In some cases a portion of these high boiling materials may beadvantageously included in the charge to the catalytic alkylation stepand in such a case may be passed from pipe I31 through pipe I40controlled by valve Ill to pipe I33, or may be removed as a separatefraction from separating means I32.

Normal butane can be converted inexpensively and with quite satisfactoryyields into aromatic hydrocarbons by being subjected to hightemperatures' and low pressures, and the aromatic hydrocarbons soproduced will iorm valuable constituents of premium motor i'uels. If itis desired to produce such aromatics, a portion of the normal butanefraction may be passed from pipe I20 through pipe I22 and pipe Icontrolled by a valve I45 to an aromatization unit I 40. In this unitthe normal butane fraction is converted at a relatively high temperatureof the order of l300-2000 F., more preferably 1400-1750 F., at a lowpressure, not substantially in excess of about 200 pounds per squareinch, for a reaction time of about 0.01-0.5 second in the absence ofcatalysts to produce a satisfactory yield of aromatic hydrocarbons.Catalysts such as are known to the art may be used, but satisfactoryoperation may be obtained in the absence of catalysts. The reactioneiiluents are passed through pipe I41 to separating means I00.Undesirably heavy hydrocarbon material and tar may be removed through apipe I controlled by a valve I02 and discharged from the system. Adesirable aromatic fraction in the gasoline boiling range may be removedthrough a pipe I58 and passed through a valve I54 to pipe 255 forblending into a final motor fuel product as will be described. If it isdesired to separate any portion of this aromatic stream, for thepreparation of aromatic products, such a. portion may be separated frompipe I03 through pipe I55 controlled by a valve I00. Any undesirablelight material may be removed from separating means I50 through a pipeI01 controlled by valve I58. If it is desired to recycle a normal butanefraction from the emuent of the aromatization unit it may be included inmaterial separated through pipe I01. and after subsequent purificationmay be reintroduced into the system as through pipe I42, controlled byvalve I, or more directly to the aromatization unit by means not shown.Inasmuch as the C4 fraction will contain an appreciable portion 01'unsaturated hydrocarbons suitable for use in the catalytic alkylationstep such a fraction may be removed from separating means I00 throughpipe I00 controlled by a valve IOI and passed to pipe I" for reaction ashas been described.

In most instances the isopentane separated from the material chargedthrough pipe I0 to the process is suitable, without further conversion,as a blending stock. It is also an excellent revalve I00 unit 184. Theisomerizatiorr asvao'rr actant for the catalytic alkylation unit 00 andany desired portion may be treated in this manner. An isopentanefraction may be removed from separating means II through pipe I02corrtrolled by a valve I08 and may be passed through directly to pipe200 for blending with the finished product or the process. I! desired aportion may be discarded from the process through pipe I00 controlled bya valve 608. Any portion desired for the catalytic alkylation may bepassed from pipe I02 through pipe It! controlled by a valve I08 to pipeI03. In some instances it may be desirable that the catalytic allwlationbe conducted with isopentane as the low boiling isoparafllnic reactant,in which case. the material passing through pipe I01 will constitute theprincipal isoparaflinic charge to this step. Isopentane from an outsidesource may be added to the system, if desired through pipe 00 controlledby valve 09 to pipe I 02.

Normal pentane, although it does not have as high an octane number asisopentane. may also at times be included directly in the finishedgasoline without subsequent treatment. However, on account of its lowoctane number we generally prefer to subject it to an operation whichwill make it more desirable for use as a gasoline blending stock. Suchtreatment may be either dehydrogenation, producing pentenes which may beblended directly into the gasoline or which may serve as reactants forthe catalytic allsylation, or the normal pentane may be subjected to anisomerization or reforming, either by itself or in combination withother higher boiling hydrocarbons or low octane number as will besubsequently described. A normal pentane fraction is removed fromseparating means II through pipe I10 controlled by valve I1 I. A portionthereof may be passed through a valve I 12 to a dehydrogenation unitI13, which should be operated under substantially the same operatingconditions just described for the dehydrogenation unit I in which normalbutane is dehydrogenated. The eilluent of dehydrogenation unit I13 ispassed through a pipe I14 to suitable separating means I10. Undesirablelow boiling material which will be primarily hydrogen and methane may bedischarged through a pipe I10 controlled by a valve I11. A pentenefraction produced by the dehydrogenation may be removed through pipe I10and passed directly to the catalytic alkylation unit 95 through valveI19 into pipe I 33. If it is desired to blend any portion of this normalpentene fraction directly with the gasoline it ma be passed from pipeI18 through pipe I80 controlled by a valve I8I to pipe I22 and on topipe 255.

In some instances it may be desirable to isomerize the normal pentanefraction to produce isoparafllns such as isopentane and/or isobutane,which may be recovered as such for blending with the final gasolineproduct, or which may be passed to the catalytic alkylation unit 95. Tothis end any desirable portion of the normal pentane fraction may bepassed from pipe I10 through a pipe I82 controlled by a valve I83 toisomerization may be conducted by any suitable conditions known to theart and is preferably conducted at a temperature between about 0 and 400F. and a pressure suflicient to maintain the hydrocarbon material inliquid phase and in the presence 01' an isomerization catalyst such asaluminum chloride or aluminum bromide. The isomerization eflluent ispassed through a pipe I85 controlled by a valve I80 to aavao'rv suitableseparation means I81. Heavy material, which may include a sludge whichcontains an isomerization catalyst if the isomerization unit in I84 isoperated under conditions such as to produce such a material, may beremoved through pipe I88 controlled by valve I89. Any undesirable lowboiling material may be removed through a pipe I90 controlled by a valveI9I. A suitable isoparaflin fraction produced by the isomerization isremoved through a pipe I92 and may be passed through valve I93 to pipe255 for blending in the finished gasoline product, or any desiredportion thereof may be discharged from the system through pipe I94controlled by valve I95. This isoparaflin fraction will contain materialwhich is highly desirable, as discussed, for charge to the catalyticalkylation unit 95 and any portion desired for such reaction may bepassed from pipe I92 through pipe I95 controlled by a valve I91. Anormal paraiiin fraction may be separated from means I81 and returned toisomerization unit I84 through pipe I98 controlled by valve I99. Normalpentane from a separate source for treatment within the process'may beintroduced to pipe I10 through pipe I59 and valve I09. Material sointroduced may include recycled material from one or more of theconversion steps.

In some instances it may be desired to blend a portion of the normalpentane fraction directly in the finished gasoline product, in whichcase it may be passed from pipe I10 through pipe 200 controlled by avalve I to pipe I22. In case it is desired to subject a portion of thenormal pentane fraction to isomerization or reforming in conjunctionwith other fractions of low octane number, a portion suitable for thismay be passed from pipe 200 through pipe 202 controlled by valves 203and 204 to pipe 201 passing to the reforming unit 208, to be described.

In many instances it will be found desirable to subject the hexanes andheavier fraction to a reforming operation to improve its octane num ber.When this fraction is shown-by analysis, as by careful fractionalseparation and testing of individual fractions, to be. comprisedpredominantly of hydrocarbons of low octane numbers, the entire fractionmay be subjected to reforming by being passed from separating means IIthrough a pipe 205 controlled by valve 205 to pipe 202 and through valve204 to pipe 201 and reforming unit 208. In those'cases where it is notnecessary to reform this hexanes and heavier fraction, or at least notto treat all of it in this manner, it may be passed from pipe 205 topipe 202 and through valve 203 to pipe 200, and through valve 20I topipes I22, and 255 for blendmany instances it will be found by suitableanalysis that the hexanes and the heavier fraction will containsubstantial portions of hydrocarbons of low octane number andsubstantial portions of hydrocarbons of high octane number, and thatsuch portions may be advantageously separated from each other andonlythe fractions of low octane number subjected to a reforming operation.In such a case the hexanes and heavier fraction may be passed from pipe205 through a pipe 2I0 controlled by a valve 2 to a suitable separatingmeans illustrated by a fractionating column 2I2. From the separatingmeans 2 I2 there may be separated one or more fractions of low octanenumber and one or more fractions of high octane number. While theseparating means 2I2 is shown as a fractionating column, it is to beunderstood that any suitableknown method of carrying outthe separationdesired ior any particular hexanes and heavier fraction may bepracticed, and in fact, many of the fractions may be more preferablyseparated by means of selective solvents which will separate aromatic ornaphthenic hydrocarbons from paraflinic hydrocarbons. Such selectlvesolvent extraction methods may, of course, be operated in combinationwith suitable fractional distillation units to effect the desiredseparations, as will be readily understood, and applied, by one skilledin the art. Material in the hexanes and heavier range from an outsidesource may be added, as desired, to the process through pipe 231controlled by valve 238 to pipe 205.

In the present process fractions of high octane number are shown asbeing separated, from the material charged through pipe 2I0, by means ofpipes 2I3, 2I4 and 2I5 controlled by valves 2I5, 2I1 and 2I8respectively. Such fractions will comprise highly branched parafllnhydrocarbons, aromatic hydrocarbons, some of the lower boilingnaphthenes, and/or the like. The fractions from. pipes 2 I4 and 2 I5 maybe blended with the fraction in pipe 2I3 and passed through valve 2I9 topipe 255 for subsequent blending in a finished gasoline product, or maybe discharged from the system through pipe 220 controlled by a valve22I. Selected fractions may be removed from the process as from pipe 2through pipe 222 controlled by a valve 223, and from pipe 2I5 throughpipe 224 controlled by a valve 225. Fractions of low octane number,primarily more or less straight-chain paraflins, may be removed from thematerial passing through pipe 2I0 through pipes 226, 221 and 228controlled by valves 230, 23I and 232 respectively. fractions of lowoctane number may be blended together by being passed to pipe 201 andare subjected to a reforming in unit 208. Selected fractions for anysuitable use may be removed from one or more of these streams as bybeing passed frompipe 221 through pipe 233 controlled by a valve 234, orfrom pipe 228 through pipe 235 controlled by a valve 236.

The material of low octane number passed through pipe 201 to reformingunit 208 may be treated in anysuitable manner to improve its octanenumber. This treatment may be carried out as an isomerization treatmentunder conditions similar to those described for the isomerization unitI84 or may be carried out by any suitable thermal reforming treatment atelevated temperatures and pressures.

However, we prefer to improve the octane number of this material bytreating it in the presence of a catalyst under conditions such thatthere is a minimum of production of normally gaseous material or aminimum change in the boiling range characteristics of the materialtreated. Such a catalytic reforming may be carried out by passing thehydrocarbon stock over a suitable solid granular catalyst such asbauxite or other mineral materials, either alone or impregnated withsuitable materials such as chromium oxide. For these operations thetemperatures should be in the range of about 750 to 1100 F. preferablyin the range of about 900-1050 F. under a pressure not substantially inexcess of about pounds per square inch, preferably within the range of5-30 pounds per gauge, and at a flow rate of about 0.5 to 5 liquidvolumes of hydrocarbons charged per volume of space occupied by thegranular catalyst per hour. Under these con- These ditionsdehydrogenation and isomerization reactions take place with a minimumformation of light gases other than hydrogen. Free hydrogen may or maynot be added to'the charge to such a treatment as by being introduced topipe 241 by means not shown, as may be found desirable. Of thehydrocarbon gases produced the major portion is .C: and C4 unsaturatedhydrocarbon material which can be subsequently'used in other steps ofthe process as will be described. For example, in such a treatment therewas produced, for every barrel of hydrocarbon stock charged, about 247cubic feet of C4 and lighter gases, which were predominantly freehydrogen and of which about 82 cubic feet comprised Ca and C4hydrocarbons, of which over 70 mol per cent were oleilns.

The eiiiuent of the reforming unit 204 is passed through pipe 240 to aseparation unit 2 which may include fractional distillation units and/orselective solvent absorption units as will be found most desirable. Areformed gasoline stock of high octane number is removed from separationunit 2 through a pipe 242 and is passed through a valve 242 to pipe 255for blending with other stocks which are passed to pipe 255 to produce afinished motor fuel of gasoline characteristics and of high octanenumber. Any portion of the material passing through pipe 242 may beremoved from the system through pipe 249 controlled by a valve 244.Light gases comprising primarily free hydrogen and methane and C1;hydrocarbons may be removed through the system through pipe 245controlled by a valve 246. C: and C4 hydrocarbons, which will bepredominantly unsaturated and highly suitable as a por-- tion of thecharge stock to the catalytic alkylation unit 95, may be removed fromseparation unit 2 through pipe 241 controlled by a valve 248 and passeddirectly to pipe53. Any heavy undesired material may 25! controlled by avalve 25L A hydrocarbon stock-in the gasoline range of low octanenumber, or a portion of the stock passed through pipe 242, may be passedfrom separation unit 2 through pipe 252 controlled by a valve 253 topipe 228 for subsequent retreatment in the reforming unit 205. When thisrecycle stock comprises a portion of the material removed through pipe242 the result will be, after a steady state of operation has beenreached, a higher octane number for the material passing through pipe242. when selective solvent extraction is employed in the separationunit 24I, a separation may be readily accomplished between products ofhigh octane number and unreacted material of low octane number, whichlatter can then be recycled through pipe 252 for retreatment.

A portion of the isopentane fraction produced in the thermal alkylationreaction zone 33 and removed from separation unit 42 through pipe 4'!may be passed therefrom through pipe 255 controlled by a valve 256 andblended with the reformed hexanes and heavier fraction passing throughpipe 242. Other hydrocarbon fractions produced in the process and passedthrough pipes I, I5, I53, I62, I92, H3, 242, and/or I22, controlled byvalves H0, 56, I54, I54, I93, 2I9 243, and I24, respectively, may beblended in pipe 255, to produce a motor fuel of gasoline characteristicsas a final product of the process.

The reformed hexanes and heavier fraction and the catalytic alkylatewill be the principal stocksof low volatility, and to these materials itis necessary to add one or more additional hybe removed through pipescram":

drocarbon fractions of higher volatility to produce a finished motorfuel of gasoline characteristics- In most cases it will be necessary toadd two or more of the other fractions described herein. Isopentane maybe added directly from the separating means I I or may be added as aproduct of a process of the alkylation unit 33. The aromatichydrocarbons produced in the aromatization of normal butane will beintermediate in volatility between the stocks of low volatility andstocks of high volatility. The neohexane fraction will be relativelyhigh as to volatility and octane number, but will be low as to vaporpressure. Appreciable amounts of normal butane may be used directly as aresult of the production of considerable quantities of a stock ofextremely low volatility by the catalytic alkylation unit. When treatingan initial stock charged through pipe II which contains appreciableamounts of sulfur compounds, they should be removed so as not to exceedthe limits required by specifications for the final product. Most sulfurcompounds present in the lighter fractions may be removed by simplealkali washes, carried out where necessary by apparatus not shown. Thetreatment described as preferred for the reforming unit 208 alsoconverts the majority of the sulfur compounds which may be present inthe hexanes and heavier fraction treated therein, and resulting hydrogensulfide, or the like, is readily removed by suitable treatment such asan alkali wash, or distillation, forming a part of separation unit 2.Other known desulfurization operations may be carried out where suitableor necessary, as can be readily determined and applied by one skilled inthe art.

It will be readily appreciated that our invention comprises combinationsof process steps, each of which is separately known to the art, and thatthe accompanying flow sheet is diagrammatic only. some of the processsteps are operated under quite high superatmospheric pressures, whileothers are operated under relatively low pressures, which may at timeseven be subatmospheric. For all of the process steps desirable operatingconditions and ranges have been disclosed and discussed, and in allcases flows of materials treated and produced have been shown. Theadaptation of our invention, or any particular modification thereof, tooperation on a commercial scale with commercial epuipment such as pumps,compressors, heat exchangers,

heating units and furnaces, cooling catalyst chambers and reactors,separating equipment such as fractional distillation columns, absorbers,and solvent extractors, etc., may be readily made by one skilled in theart in view of the teachings of the present disclosure. Variousmodifications of our invention may be carried out without departing fromthe spirit of the disclosure or from the scope of the claims.

We claim:

1. A process for converting normally gaseous hydrocarbons having two tofour carbon atoms per molecule into hydrocarbons boiling in the gasolinerange, which comprises reacting propane with ethylene under noncatalyticalkylation conditions to form pentanes and recovering from eilluents ofsaid alkylation an isopentane fraction so produced and containing aminor amount of olefins, separately reacting isobutane with ethyleneunder noncatalytic alkylation conditions to form hexanes and recoveringfrom eflluents of the last said alkylation a hexane fraction so producedand an unreacted isobutane fraction containing a minor amount ofoiefins, passing to a catalytic alkylation step said isopentane fractionand said unreacted isobutane fraction to react oleflns contained thereinwith said isoparaflins to form a normally liquid paraflinic fractionboiling aforesaid hexane fraction to produce a. gasoline of high octanenumber.

2. A multistage process for the conversion of substantially all of thenatural gas hydrocarbons heavier than methane and boiling in and belowthe gasoline range contained in a hydrocarbon mixture recovered from awet natural gas to a hydrocarbon material having gasolinecharacteristics, which comprises separating from a wet natural gas afraction comprising ethane, a fraction comprising propane, a fractioncomprising isobutane, a fraction comprising normal butane, a

fraction comprising a pentane, and a fraction in the gasoline boilingrange of relatively low antiknock value and comprising heavierhydrocarbons, said fractions together comprising essentially all of thehydrocarbon material heavier than methane and boiling in and below thegasoline range originally in said wet natural gas, dehydrogenating saidethane fraction to form ethylene, reacting ethylene 50 produced with aportion of said propane to form predominantly saturated hydrocarbonscomprising isopentane, separating from the effluent an isopentanefraction, dehydrogenating a further portion of said propane to formpropylene, reacting said propylene, said isobutane, and said isopentanefraction from said alkylation in a catalytic alkylation step to form.predominantly saturated hydrocarbons in the gasoline boiling range ofrelatively high antiknock value, reforming said heavier fraction toincrease the antiknock value thereof without materially changing theboiling characteristics, and blending said normal butane, said naturalpentane fraction, said reformed heavier fraction, and said catalyticalkylate in the gasoline range to produce a composite hydrocarbon liquidhaving gasoline characteristics of boiling range, vapor pressure andvolatility and having a high antiknock value.

8. A process for the production of a normally liquid hydrocarbonmaterial of gasoline characteristics and relatively high antiknockvalue, which comprises separating from a natural gas a hydrocarbonmaterial comprising substantially all of the hydrocarbons having two andmore carbon atoms per molecule including normally liquid hydrocarbons inthe gasoline boiling range and of relatively low antiknock value,separating from said hydrocarbon material an ethane fraction, a propanefraction, an isobutane fraction, a normal butane fraction, a pentanefraction, and a natural gasoline fraction in the gasoline boiling rangeof relatively low antiknock value, dehydrogenating said ethane fractionto form ethylene and recovering ethylene so produced,dehydrogenatingsaid propane fraction to form propylene and recovering a propylenefraction so produced, reacting said ethylene with said isobutanefraction under noncatalytic alkylating conditions to form isomerichexanes and recovering a resultant alkylate fraction in the gasolineboiling range and an unreacted isobutane fraction, dehydrogenatingat'least a part of said normal butane fraction to produce butenes andrecovering a butene fraction so produced, reacting said unreactedisobutane fraction, said propylene fraction and said butene fractionunder catalytic alkylation conditions to form a catalytic alkylate andrecovering a catalytic alkylate in the gasoline boiling range soproduced, subjecting said natural gasoline fraction of low antiknockvalue to a catalytic treatment at elevated temperature to increase theantiknock value without essentially changing the boilingcharacteristics, recovering a reformed natural gasoline so produced, andblending said reformed natural gasoline, said catalytic alkylatefraction, said noncatalytic alkylate fraction, said pentane fraction anda portion of said normal butane fraction to produce a liquid hydrocarbonmaterial having gasoline characteristics of boiling range, vaporpressure and volatility and of relatively high antiknock value.

4. A process for producing a balanced gasoline of premiumcharacteristics from the ethane and heavier constituents of a wetnatural gas, which comprises separating from a wet natural gas anethane-propane fraction, an isobutane fraction,

and a natural gasoline fraction in the gasoline boiling range, saidfractions together comprising eflluents an ethylene fraction, reactingsaid ethyl-,

ene fraction and said isobutane fraction under noncatalytic alkylationconditions to produce a noncatalytic alkylate comprising isohexanes andseparating from the eilluent a noncatalytic a1- kylate fraction in thegasoline boiling range, reacting a portion of said normal butanefraction under aromatizing conditions to produce low boiling aromaticsand separating from the eiiluent an aromatic fraction in the gasolineboiling range, separating by fractional distillation said naturalgasoline fraction into a fraction comprising predominantly constituentsof poor antiknock values and a fraction comprising predominantlyconstituents of good antiknock values, catalytically reforming said poorantiknock fraction to improve the antiknock value without materiallyaltering the boiling characteristics and recovering from the eflluent areformed natural gasoline fraction, and blending together said reformedfraction, said high antiknock natural gasoline fraction, said aromaticfraction, said noncatalytic alkylate fraction, said isopentane fraction,and a portion of said normal butane fraction to form a balanced gasolineof high antiknock value and containing all the hydrocarbon materialobtained from the aforesaid fractions.

5. A process for producing a high yield of a liquid hydrocarbon Imaterial having gasoline characteristics of boiling range and vaporpressure, and of relatively high antiknock value from a wet natural gas,which comprises separating from said wet natural gas to anethane-propane fraction, an isobutane fraction, a normal butanefraction, a pentane fraction, and a hexane and heavier fraction in thegasoline boiling range, said fractions together comprising substantiallyall of the hydrocarbon material heavier than methane and boiling in andbelow the gasoline range originally in said wet natural gas,dehydrogenating said ethane-propane fraction to form ethyleneandpropylene and separating from the eflluents an ethylene-propylenefraction so produced, re-' acting said ethylene-propylene fraction withsaid isobutane fraction under noncatalytic alkylating conditions to formlow boiling normally liquid,

a normal butane fraction, an isopentane fraction,

predominantly parafllnic hydrocarbons and separating from the eifluentsa noncatalytic alkylate fraction in the gasoline boiling range, soproduced, subjecting at least a portion of said normal butane fractionto an elevated temperature and relatively low pressure to form lowboiling, normally liquid, predominantly aromatic hydrocarbons' andseparating from the effluents an aromatic fraction in the gasolineboiling range, separating said hexanes and heavier fraction into afraction of high antiknock value and a fraction of low antiknock value,subjecting said low antiknock fraction to a catalytic reforming atelevated temperature to improve the antiknock value without substantialchange in boiling characteristics, and recovering the resultanthydrocarbons in the gasoline boiling range, and blending said reformedfraction, said high antiknock hexanes and heavier fraction, saidaromatic fraction and said alkylate fraction together with said pentanefraction and a portion of said normal butane fraction to form a liquidhydrocarbon material containing all the hydrocarbon material obtainedfrom the aforesaid fractions and having gasoline characteristics ofboiling range and vapor pressure and of relatively high antiknock value.

6. A process for producing a high yield of a liquid hydrocarbon materialhaving gasoline characteristics of boiling range and vapor pressure andof relatively high antiknock value from a wet natural gas, whichcomprises separating from said wet natural gas an ethane fraction, a

. propane fraction, an isobutane fraction, a normal butane fraction, anormal pentane fraction, and

a hexane and heavier fraction in the gasoline boiling range, saidfractions together comprising substantially all of the hydrocarbonmaterial heavier than methane and boiling in and below the gasolinerange originally in said wet natural gas, dehydrogenating said ethanefraction to form ethylene and recovering an ethylene fraction soproduced, dehydrogenating a portion of said propane fraction to producepropylene and recovering a propylene fraction so produced, reacting aportion of said ethylene fraction and a further portion of said propanefraction under noncatalytic alkylating conditions to produce highlyvolatile normally liquid predominantly paraflinic hydrocarbons andrecovering from the efiluents a pentane fraction so produced, reactingsaid isobutane fraction and a further portion of said ethylene fractionunder noncatalytic alkylating conditions to form low boiling normallyliquid predominantly parafllnic hydrocarbons and separating from theeffluents a noncatalytic alkylate fraction in the gasoline boiling rangeso produced, separating also an unreacted isoparaflin fraction,subjecting said hexanes and heavier fraction to catalytic reforming atan elevated temperature to increase the antiknock value thereof withoutsubstantial change in boiling characteristics, separating a reformedfraction from the eflluents, separating also a C3-C4 fraction,subjecting in admixture said C3-C4 fraction, said unreacted isoparafilnfraction, said non'catalytie 'alkylate pentane fraction and saidpropylene fraction to catalytic alkylation to form a catalytic alkylateand separating from the eilluents a catalytic alkylate fraction in thegasoline boiling range, and blending said catalytic alkylate fraction,said noncatalytic alkylate fraction, said reformed fraction, and saidnormal butane and said normal pentane fraction to produce a normallyliquid hydrocarbon material containing all the hydrocarbon materialobtained from the aforesaid fractions and with gasoline characteristicsof boiling range and vapor pressure and of relatively high antiknockvalue.

7. A process for the production of a motor fuel having gasolinecharacteristics of boiling range and vapor pressure and a relativelyhigh antiknock value from a Wet natural gas containing normally gaseoushydrocarbons heavier than methane and normally liquid hydrocarbons inthe gasoline boiling range, which comprises separating from saidhydrocarbon mixture an ethanepropane fraction, a propane fraction, anisobutane fraction, a normal butane fraction, an isopentane fraction, 2.normal pentane fraction, a natural gasoline fraction boiling in thegasoline range of high antiknock value, and a natural gasoline fractionboiling in the gasoline range of low antiknock value, said fractionstogether representing substantially all the hydrocarbons originally insaid wet natural gas heavier than methane and boiling in and below thegasoline boiling range, dehydrogenating said ethane-propane fraction toproduce ethylene and recovering from eflluents of said dehydrogenationan ethylene fraction, dehydrogenating a portion of said propane fractionto produce propylene and recovering from efiiuents of saiddehydrogenation a propylene fraction, reacting a portion of saidethylene fraction and a further portion of said propane fraction underalkylation conditions to produce highly volatile normally liquidpredominantly paraffinic hydrocarbons and recovering from effluents ofsaid alkylation a pentane fraction so produced, reacting a, furtherportion of said ethylene fraction and a portion of said lsobutanefraction under alkylation conditions to produce low-boiling normallyliquid predominantly paraflinic hydrocarbons and separating fromeflluents of said alkylation an alkylate fraction so produced andboiling in the gasoline range, separating also from eiiiuents of saidalkylation an unreacted isoparaflin fraction, subjecting a portion ofsaid normal butane fraction to aromatizing conditions to producelow-boiling aromatic hydrocarbons and also normally gaseous olefins byconcomitant dehydrogenation reactions, separating from effluents of saidaromatizing an arcmatic hydrocarbon fraction boiling in the gasolinerange, separating also from said aromatizing a normally gaseous olefinfraction, subjecting said normal pentane fraction to catalyticisomerization to form low-boiling isoparaflins and recovering fromeffluents of said isomerization a low boiling isoparaifin fraction,subjecting said natural gasoline fraction of low antiknock value toreforming conditions to produce a stock of a higher antiknock value andsubstantially the same boiling characteristics and minor amounts ofolefinic C3 and C4 hydrocarbons by minor concomitant cracking reactions,separating from efiluents of said reforming a reformed fraction boilingin the gasoline range, separating also from eiliuents of said reforminga C3-C4 fraction, subjecting in admixture said C3-C4 fraction, theaforesaid pentane fraction from said propane alkylation, said propylenefraction, the aforesaid unreacted isoparaffin fraction, a furtherportion of said isobutane fraction, the aforesaid low-boiL ingisoparailin fraction, and the aforesaid normally gaseous olefin fractionfrom said aromatizing to catalytic alkylation to form a catalyticalkylate, separating from efiluents of said catalytic alkylation acatalytic alkylate fraction boiling in the gasoline range, and blendingsaid catalytic alkylate, said alkylate fractionfrom isobutanealkylation, said aromatic fraction, a further portion of said normalbutane fraction, said isopentane fraction, said natural gasolinefraction of high antiknock value, and said reformed fraction to producea normally liquid hydrocarbon material containing all the hydrocarbonmaterial obtained from the aforesaid fractions and with gasolinecharacteristics of boiling range and vapor pressure and of relativelyhigh antiknock value.

8. A process for the production of a motor fuel having gasolinecharacteristics of boiling range and vapor pressure and a relativelyhigh antiknock value from a saturated hydrocarbon mixture containingnormally gaseous hydrocarbons heavier than methane and normally liquidhydrocarbons in the gasoline boiling range, which comprises separatingfrom said hydrocarbon mixture an ethane-propanefraction, apropane-fraction, an isobutane fraction, a normal butane fraction, apentane fraction, a natural gasoline fraction boiling in the gasolinerange of high antiknock value, and a natural gasoline fraction boilingin the gasoline range of low antiknock value, said fractions togethercomprising substantially all of the hydrocarbon material heavier thanmethane and boiling in and below the gasoline range originally in 'saidwet natural gas, dehydrogenating said ethane-propane fraction to produceethylene and recovering from efliuents of said dehydrogenation anethylene fraction, dehydrogenating a portion of said propane fraction toproduce propylene and recovering from efliuents of. said dehydrogenationa propylene fraction, reacting a portion of said ethylene fraction and afurther portion of said propane fraction under alkylation conditions toproduce hi hly volatile normally liquid predominantly paraflinichydrocarbons and recovering from eilluents of said alkylation a pentanefraction so produced, reacting a further portion of said ethylenefraction and a portion of said isobutane fraction under alkylationconditions to produce low-boiling normally liquid predominantlyparaiilnic hydrocarbons and separating from efliuents of said alkylationan alkylate fraction so produced and boiling in the gasoline range,separating also from emuents of said alkylation an unreacted isoparailinfraction, subjecting a portion of said normal butane fraction toaromatizing conditions to produce low-boiling aromatic hydrocarbons andalso normally gaseous olenns by concomitant dehydrogenation reactions,separating from eflluents of said aromatizing an aromatichydrocarbonfraction boiling in the gasoline range, separating also fromsaid aromatizing a normally gaseous olefin fraction, subjecting saidnatural gasoline fraction of low antiknock value to reforming conditionsto produce a'stock of a higher antiknock value and substantially thesame boiling characteristics and minor amounts of olefinic C3 and C4hydrocarbons by minor concomitant cracking reactions, separating fromeilluents of said reforming a reformed fraction boiling in the gasolinerange, separating also from effluents of said reforming a C3-C4fraction, subjecting in admixture said C1-C4 fraction, the aforesaidpentane fraction from said propane alkylation, said propylene fraction,the aforesaid unreacted isoparamn fraction,

a further portion of said isobutane fraction, and the aforesaid normallygaseous olefin fraction from said aromatizing to catalytic alkylation toform a catalytic alkylate, separating from emuents of said catalyticalkylation a catalytic alkylate fraction boiling in the gasoline range,and blending said catalytic alkylate, said alkylate fraction fromisobutane alkylation, said aromatic fraction, 9. further portion of saidnormal butane fraction, said pentane fraction, said natural gasolinefraction of high antiknock value, and said reformed fraction to producea normally liquid hydrocarbon material containing all the hydrocarbonmaterial obtained from the aforesaid fractions and with gasolinecharacteristics of boiling range and vapor pressure and ofv relativelyhigh antiknock value.

9. A process for producing a high yield of a liquid hydrocarbon materialhaving gasoline characteristics of boiling range and vapor pressure anda relatively high antiknock value from a wet natural gas, whichcomprises separating from said wet natural gas an ethane-propanefraction, a propane fraction, an isobutane fraction, a normal butanefraction, a pentane fraction, a natural gasoline fraction boiling in thegasoline range and having a high antiknock value, and a natural gasolinefraction boiling in the gasoline range and having a low antiknock value,said fractions together representing essentially all of the hydrocarbonmaterial originally present'in said wet natural gas heavier than methaneand boiling in and below thegasoline boiling range, dehydrogenating saidethane-propane fraction to form ethylene and separating from eiiiuentsof said dehydrogenation ethylene so produced, reacting said propanefraction with a portion of said ethylene under noncatalytic alkylationconditions to form pentane and recovering from eflluents of saidalkylation an isopentane fraction so produced containing a minor amountof olefins, separately reacting said isobutane fraction with theremainder of said ethylene under noncatalytic alkylation conditions toform hexanes and recovering from effluents of the last said alkylation ahexane fraction so produced and an unreacted isobutane fractioncontaining a minor amount of olefins, passing to a catalytic alkylationstep said isopentane fraction and said unreacted isobutane fraction toreact olefins containing therein with said isoparaillns to form anormally liquid parafiinic fraction boiling in the gasoline range,separating from eflluents of said catalytic alkylation a gasoline rangefraction so produced, subjecting a portion of said normal butanefraction to an elevated temperature and relatively low pressure to formlow-boiling normally liquid aromatic hydrocarbons and separating fromeifluents thereof an aromatic hydrocarbon fraction in the gasolineboiling range so produced, subjecting said natural gasoline fractionhaving a low antiknock value to reforming conditions to producehydrocarbons having rela tively high antiknock value and separating fromeflluents of said reforming a reformed fraction boiling in the gasolinerange and of relatively high antiknock value so produced, blending saidfraction from catalytic alkylation, said hexanes and heavier fractionfrom said noncatalytic isobutane alkylation, said aromatic fraction, afurther portion of said normal butane fraction, said pentane fraction,said natural gasoline fraction having a high antiknock value, and saidreformed fraction to produce a normally liquid hydrocarbon materialcontaining all the hydrocarbon material obtained from the aforesaidfractions and boiling in the gasoline range, and having gasolinecharacteristics of boiling range and vapor pressure and having arelatively high antiknocl: value.

GEORGE G. OBERFEIL. JEAN P. JONES.

